Water is essential to the human survival. It accounts for approximately 70% of the human body by mass (excluding fat). Water is an imperative part of human's metabolic and other biological processes. In the U.S., an average American adult ingests about 2.0 liters of water per day. Access to clean and healthy drinking water on a daily basis is not a given in many developing countries. People have inadequate access to clean water and have to routinely consume water that contain unacceptable levels of disease pathogens, toxins, harmful chemical and biological contaminants. Drinking such water can lead to acute and chronic illnesses and remains a major heath risk in many countries. For example, nitrates from fertilizer runoff can pose serious health risks. Roughly half of the world's hospital beds are occupied by patients suffering from waterborne diseases. Even in developed countries, waterborne diseases due to lack of portable or home-based clean water sources can cause public health issues. Another common problem is lead, which can be especially dangerous to the mental and physical development of children.
In addition to having minimal undesirable contaminants, truly healthy and beneficial drinking water should also have certain necessary minerals and trace elements. A number of minerals and trace elements are required to support human biochemical and physiological processes (e.g., by serving structural and functional roles as well as electrolytes). In processes aimed at providing clean and safe drinking water, the resulting water often does not contain the desired levels of mineral nutrients (e.g., calcium, magnesium, potassium, phosphorus, sulfur). Distilled or purified water, for example, may lack the balanced essential minerals found in natural spring water.
There are two conventional approaches to water treatments. One is centralized treatment where water is treated at major plants or establishments and is delivered to consumers by pipes or containers. Another approach is point-of-use (POU)/point-of-entry (POE), where water is treated right before consumption. Each treatment approach has advantages and disadvantages. For the centralized system, usually an inline or off line water quality-monitoring device is installed to make sure to monitor the quality of the production. However, centrally treated water has to be delivered to consumers either by pipes or containers, often made with metallic or plastic materials. These delivery mechanisms can introduce contaminations during transportation process such that even the water was of good quality when produced, the consumer drinks water that is no longer safe and healthy, for example, due to contaminations by heavy metals or microbiological pathogens that are often detected in tap water and bottle water.
Certain disinfectants like ozone or chlorine based chemicals are often added to the treated water to preserve the water from microbiological contaminant. These disinfectants, if properly used in minimal quantities can generally be considered as safe, may affect a consumer's health with extended long-term consumption and accumulation.
POU/POE is more advantageous in providing drinking water to the public. In the POU/POE approach, water is treated right before consumption, which minimizes the chance of re-contamination of water after it is treated. However, except with a reverse osmosis (RO) system, it is very difficult to provide inline or off line water test for the individual consumer due to the high cost. Therefore, the end user really cannot know whether the water is safe and healthy at the point of consumption. POU/POE devices (e.g., pitchers, faucet-mounting devices, and bench top or under the sink systems) are quite popular with the public now. The customer, however, can only assume that the filtration/purification systems in these devices can achieve what is claimed by the manufacture. Unfortunately, many products do not consistently provide quality drinking water as claimed, which makes POU/POE without water quality monitoring/alerting device not the best choice for customers.
Therefore, there is a continued need for novel systems and methods that provide clean, safe, healthy and disinfectant free drinking water to the individual consumer with quality assurance.